Shown in the figure is a shell made of a conductor. It has inner radius ‘a’ and outer radius ‘b’, and carries charge ‘Q’. At its centre is a dipole as shown. In this case:

• A. Surface charge density on the inner surface is uniform and equal to \(\frac{{\left( {{\rm{Q}}/2} \right)}}{{4\pi {{\rm{a}}^2}}}\)
• B. Electric field outside the shell is the same as that of a point charge at the centre of the shell
• C. Surface charge density on the outer surface depends on \(\left| {\vec p} \right|\)
• D. Surface charge density on the inner surface of the shell is zero everywhere